Add haptic feedback, rich task completion, and Google Sign-In preparation

- Add platform haptic feedback abstraction (HapticFeedback.kt) with
  implementations for Android, iOS, JVM, JS, and WASM
- Enhance CompleteTaskDialog with interactive 5-star rating, image
  thumbnails, and haptic feedback
- Add ImageBitmap platform abstraction for displaying selected images
- Localize TaskTemplatesBrowserSheet with string resources
- Add Android widgets infrastructure (small, medium, large sizes)
- Add Google Sign-In button components and auth flow preparation
- Update strings.xml with new localization keys for completions,
  templates, and document features
- Integrate haptic feedback into ThemePickerDialog

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

composeApp/src/jvmMain/kotlin/com/example/casera/platform/HapticFeedback.jvm.kt

@@ -0,0 +1,18 @@
+package com.example.casera.platform
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+
+/**
+ * JVM/Desktop implementation - no-op since desktop doesn't have haptic feedback.
+ */
+class JvmHapticFeedbackPerformer : HapticFeedbackPerformer {
+    override fun perform(type: HapticFeedbackType) {
+        // Desktop doesn't support haptic feedback
+    }
+}
+
+@Composable
+actual fun rememberHapticFeedback(): HapticFeedbackPerformer {
+    return remember { JvmHapticFeedbackPerformer() }
+}

composeApp/src/jvmMain/kotlin/com/example/casera/platform/ImageBitmap.jvm.kt

@@ -0,0 +1,19 @@
+package com.example.casera.platform
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.toComposeImageBitmap
+import org.jetbrains.skia.Image
+
+@Composable
+actual fun rememberImageBitmap(imageData: ImageData): ImageBitmap? {
+    return remember(imageData) {
+        try {
+            val skiaImage = Image.makeFromEncoded(imageData.bytes)
+            skiaImage.toComposeImageBitmap()
+        } catch (e: Exception) {
+            null
+        }
+    }
+}

composeApp/src/jvmMain/kotlin/com/example/casera/ui/components/auth/GoogleSignInButton.jvm.kt

@@ -0,0 +1,16 @@
+package com.example.casera.ui.components.auth
+
+import androidx.compose.runtime.Composable
+
+/**
+ * JVM/Desktop stub - Google Sign In not implemented for desktop
+ */
+@Composable
+actual fun GoogleSignInButton(
+    onSignInStarted: () -> Unit,
+    onSignInSuccess: (idToken: String) -> Unit,
+    onSignInError: (message: String) -> Unit,
+    enabled: Boolean
+) {
+    // No-op on JVM/Desktop
+}